GIS-based Indicators of Montana Grasshopper Communities
Abstract:We evaluated two digital data sources that might be helpful in characterizing grasshopper habitat using plant and grasshopper species composition data collected at 128 sites in three areas of Montana. A GIS was used to associate each sampling site with Omernik’s ecoregions and the Montana State Soil Geographic Database (MTSTATSGO). Detrended Correspondence Analysis (DCA) and statistical analyses were used to test for correlations among grasshopper species, available water capacity, and soil permeability across sampling areas and ecoregions. Four grasshopper species were correlated with soil permeability and six were correlated with available water capacity. MTSTATSGO plant cover percentages did not correlate with cover measured in the field, indicating inadequate resolution for the scale of this study. Ecoregions were useful in distinguishing grasshopper community gradients across Montana, from mountains to plains. These georeferenced data should be considered as input for grasshopper forecasting and decision-making models. Our results show how GIS can be used to evaluate relationships between digital data sets and ecological data gathered in the field.
Document Type: Research Article
Publication date: March 1, 2000